The ornamental design for a handbag, as shown and described.
FIG. 1 is a left front perspective view of my present invention.
FIG. 2 is a front elevation view thereof.
Fig. 3 is a rear elevation view thereof.
FIG. 4 is a left side elevation view thereof.
FIG. 5 is a right side elevation view thereof.
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a bottom plan view thereof.
No claim is made to portions that are not shown. The dash-dash lines indicate environmental and disclaimed portions to which no claim is made. The surfaces are lined for contour.